@coolman monaca preview is for development and loads everything in memory for faster debugging. If you want to test your app in real devices I’d recommend you using Monaca Debugger (and just run monaca debug in the CLI). That will put all the transpiled files in the device and refresh the app whenever you modify your code. Otherwise, just run monaca transpile to perform an actual transpilation of your coed and generate files.

@sj.meyer Also, if you want a quick way to get started, you can just add this to your project:
<link rel="stylesheet" href="https://cdn.rawgit.com/OnsenUI/OnsenUI-dist/2.0.0/css/onsenui.css" type="text/css" media="all" />
<link rel="stylesheet" href="https://cdn.rawgit.com/OnsenUI/OnsenUI-dist/2.0.0/css/onsen-css-components.css">
<script src="https://cdn.rawgit.com/OnsenUI/OnsenUI-dist/2.0.0/js/onsenui.js"></script>

Hi,
I need to change the ‘build.gradle’ file, which of these environments is the most suitable for my needs?
Today we are using the ‘Web IDE’ and I can not do that.
We already have a monaca account ‘developer’
Thank you!